These cannibal stars are routinely found in dense star clusters, where stars have many chances to feed off each other. Now, however, scientists have found blue stragglers in the Milky Way's galactic bulge, a dense region of stars and gas surrounding the galaxy's center.

From these 42 stars, researchers estimate that 18 to 37 of them are likely real blue stragglers that are about 10 billion to 11 billion years old. The remainder may be genuinely young stars in the bulge, or stars not actually in the bulge.

It's also possible the blue stragglers did not form by slamming into other stars and absorbing extra hydrogen fuel, as occurs in other parts of the universe.

Instead, the blue stragglers in the galactic bulge may have formed by ripping hydrogen off their companion stars. This possibly occurred either when one star fed off its partner in a two-star system, or perhaps after gravitational interactions in a triple-star system had caused two of its members to merge into one.

"There's still a lot we don't know about the details of how blue stragglers form," Clarkson said.

"Finding them in the bulge provides another set of constraints that can help refine models of their formation."